View source for 1fkq


==RECOMBINANT GOAT ALPHA-LACTALBUMIN T29V==
<StructureSection load='1fkq' size='340' side='right'caption='[[1fkq]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1fkq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Capra_hircus Capra hircus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FKQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1FKQ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1fkq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fkq OCA], [https://pdbe.org/1fkq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1fkq RCSB], [https://www.ebi.ac.uk/pdbsum/1fkq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1fkq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LALBA_CAPHI LALBA_CAPHI] Regulatory subunit of lactose synthase, changes the substrate specificity of galactosyltransferase in the mammary gland making glucose a good acceptor substrate for this enzyme. This enables LS to synthesize lactose, the major carbohydrate component of milk. In other tissues, galactosyltransferase transfers galactose onto the N-acetylglucosamine of the oligosaccharide chains in glycoproteins.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/fk/1fkq_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1fkq ConSurf].
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== Publication Abstract from PubMed ==
The Thr29 residue in the hydrophobic core of goat alpha-lactalbumin (alpha-LA) was substituted with Val (Thr29Val) and Ile (Thr29Ile) to investigate the contribution of Thr29 to the thermodynamic stability of the protein. We carried out protein stability measurements, X-ray crystallographic analyses, and free energy calculations based on molecular dynamics simulation. The equilibrium unfolding transitions induced by guanidine hydrochloride demonstrated that the Thr29Val and Thr29Ile mutants were, respectively, 1.9 and 3.2 kcal/mol more stable than the wild-type protein (WT). The overall structures of the mutants were almost identical to that of WT, in spite of the disruption of the hydrogen bonding between the side-chain O-H group of Thr29 and the main-chain C=O group of Glu25. To analyze the stabilization mechanism of the mutants, we performed free energy calculations. The calculated free energy differences were in good agreement with the experimental values. The stabilization of the mutants was mainly caused by solvation loss in the denatured state. Furthermore, the O-H group of Thr29 favorably interacts with the C=O group of Glu25 to form hydrogen bonds and, simultaneously, unfavorably interacts electrostatically with the main-chain C=O group of Thr29. The difference in the free energy profile of the unfolding path between WT and the Thr29Ile mutant is discussed in light of our experimental and theoretical results.

Contribution of Thr29 to the thermodynamic stability of goat alpha-lactalbumin as determined by experimental and theoretical approaches.,Horii K, Saito M, Yoda T, Tsumoto K, Matsushima M, Kuwajima K, Kumagai I Proteins. 2001 Oct 1;45(1):16-29. PMID:11536356<ref>PMID:11536356</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1fkq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Alpha-lactalbumin 3D structures|Alpha-lactalbumin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Capra hircus]]
[[Category: Large Structures]]
[[Category: Horii K]]
[[Category: Kumagai I]]
[[Category: Matsushima M]]
[[Category: Tsumoto K]]